Investigation of heat transfer performance using an oscillating vertical flat plate

摘要

In this study, the heat transfer performance of an oscillating vertical flat plate is experimentally and numerically investigated. Rayleigh number (Ra), Womersley number (Wo), and dimensionless oscillation amplitude (Ao) are changed, and the effects of these parameters on heat transfer performance are analysed. The numerical simulations are performed using a finite volume method-based computational fluid dynamics procedure, and the numerical results are validated by comparisons with the experiments. To explain the heat transfer mechanism, the instantaneous velocity and temperature profiles on the plate surface are obtained. It has been observed that the periodic oscillations continuously renewed the velocity and thermal boundary layer, increased the convection effects, and improved the heat transfer. Consequently, the heat transfer performance was significantly affected by the oscillation parameters and increased as both Wo and Ao increased for all tested Rayleigh numbers (Ra). The maximum heat transfer improvement achieved was about 45% at a high amplitude (Ao = 1.4) and frequency (Wo = 146) at Rayleigh number (Ra = 1.17 × 10~7). The results are presented as a function of dimensionless numbers.